Gelatinous dynamite composition containing a surface active agent



Patented Apr. 27, 1954 UNITED STATE AENT FFICE GELATINOUS DYNAMITECOMPOSITION CONTAINING A SURFACE ACTIVE AGENT No Drawing.

Application August 18, 1950,

Serial No. 180,313

6 Claims. 1

This invention relates to explosive compositions of the type of thenitroglycerin dynamites and more particularly to gelatinized explosivesof improved properties.

This application is a continuation-in-part of my co-pending UnitedStates application, Serial Number 655,889, filed March 20, 1946, nowabandoned.

Commercial dynamites comprise essentially nitroglycerin or itsequivalent of liquid explosive nitric esters, a carbonaceous combustibleabsorbent for the liquid explosive, and one or more inorganic oxidizingagents, particularly sodium nitrate and ammonium nitrate. One of theimportant types of such dynamites is the class of gelatin dynamites, inwhich the nitroglycerin is partially gelatinized to a thickened viscousfluid by solution therein of a predetermined quantity of nitrocelluloseof suitable characteristics. This liquid is then incorporated bythorough mixing with the solid ingredients, comprising absorbents andoxidizing agent. The completed blend is of a solid plastic consistencyand is extruded into the cylindrical paper shell that is to serve as thecontainer for the explosive. In the case of the so-ca-lled ammoniagala-tins, nitroglycerin is replaced by ammonium nitrate as theefiective explosive ingredient to as great an extent as is consistentwith retaining suiiicient plasticity to allow satisfactory woming orextruding properties, and also field properties. The amount of thisreplace ment is often limited by the plasticity require ments toquantity less than is desired.

An object of the present invention is an explosive compositioncomprising a liquid explosive nitric ester and a solid inorganicoxidizing ingredient, said composition retaining superior workingproperties even with a reduced content of liquid explosive. A furtherobject is a gelatinised nitroglycerin explosive of the above nature. Astill further object is a gelatinized nitroglycerin dynamite possessingsuperior working properties because of the inclusion in the compositionof an ingredient that promotes the plasticity oi" the mixture even withreduced content of nitroglycerin. A further object is a method ofproducing explosives of the improved properties described. Additionalobjects will be disclosed as the invention is described more at lengthhereinafter.

I have found that the reason the replacement of the liquid nitric esterwith the water soluble inorganic salts is limited is that the salts areessentially not wetted by the liquid nitric ester, and that, therefore,a homogeneous plastic mass is not produced, even With considerablemixing action. A quantity of liquid greater than desired is thusnecessary so that the mixture may have the required working propertiesand field characteristics. I have further found that the above mentioneddeficiency can be overcome by incorporating a small quantity of awetting and emulsifying agent into the explosive mixture during themixing step. The inclusion of. this small quantity of a surface activeagent causes a reduction in the interfacial tensions between thewatersoluble salts and the liquid nitric ester. and penmits theformation of a homogeneous mixture having the required plasticity evenwhen the liquid nitric ester is present in proportions appreciably lessthan heretofore believed possible.

The reduction of the interfacial tensions between the liquid nitricester and the inorganic salt is the crucial point in this invention, andmay be brought about by any surface active agent. Surface active agents,as used in this description, are compounds possessing a non-polar groupof at least eight carbon atoms, and a polar group such as hydroxy, alkylcarboxylate, amino carboxylate, sulionate, sulfate, acid phosphateester, amino, and quaternary ammonium radicals. The compounds possessingthe desired properties are esters and amides of long chain aliphaticcarboxylic acids, soaps of organic bases and of alkali metals,unsubstituted aliphatic monohydric alcohols, organic sulfonates, organicsulfate esters, long chain aliphatic amines and their salts, quaternaryammonium compounds, and esters of long chain alkyl phosphates.

The following examples will serve as specific embodiments of explosivecompositions prepared in accordance with the invention. It will beunderstood, of course, that these are by way of illustration only andare not to be considered as limiting in any way.

Example 1 A mixing of a gelatin dynamite of the following finalcomposition was made, in an amount of 6,000 grams:

introduced into the mixing bowl, the temperature maintained at about 120F. and the nitrocotton added. An amount of triethanolamine oleate wasincluded also, in an amount equal to 0.1% of the total composition. Themixture was agitated for about five minutes until the explosive solutionhad become viscous, and the blended solid ingredients were then added.After further mixing for about ten minutes, the plastic mass was removedfrom the bowl and extruded into the open ends of paper shells of 1 in.diameter and 8 in. length, closed at the further end. After filling, theopen ends of the shells were closed by folding over.

The gelatinized explosive extruded readily whereas a similarcomposition, to which no triethanolamine oleate had been added, couldnot be extruded. In analagous compositions, in which the nitroglycerincontent had been lowered to as low as 19 good extrudability was obtainedwhen the added material was present. The gelatin dynamite containing theadded triethanolainine oleate showed satisfactory stability on continuedstorage at an elevated temperature.

Example 2 An ammonia gelatin dynamite on a similar formula was made,except that the added wetting agent in the same amount was laurylaminehydrochloride, the nitroglycerin content being 23%, and other slightchanges being made. The composition extruded very satisfactorily, whilea similar composition containing no added promoter could not beextruded.

Example 3 An ammonia gelatin dynamite was made having a nitroglycerincontent of 23% and generally similar in composition to that ofExample 1. A surface active agent was introduced with the nitroglycerincomprising sorbitan monolaurate in the amount of 0.5%. Whereas a similarcomposition containing no added promoting agent could not be extruded,the composition of the present example extruded without difficulty.

Eccample 4 A similar ammonia gelatin was made of the general compositionof Example 1, and containing 23% nitroglycerin, to which was added 0.5%by weight of the entire composition of a salt of a long chain fatty acidamide. The gelatinized composition extruded very satisfactorily.

Example 5 An ammonia gelatin dynamite was made of the general formula ofExample 1, containing 23% nitroglycerin, to which an amount of thedioctyl ester of sodium sulfosuccinic acid had been added, in an amountof 0.5% of the composition. The explosive extruded satisfactorily,though a similar composition without the added plasticity promoter couldnot be extruded.

Example 6 A similar composition, in which 0.5% had been added to thenitroglycerin of a sulfate of a long chain aliphatic alcohol, possessedexcellent extrusion properties.

Example 7 An ammonia gelatin was prepared containing la-uryl pyridiniumchloride, a quaternary ammonium salt, in the amount of 0.5%, 23%nitroglycerin being present. Excellent extrusion properties wereobtained.

Example 8 A similar mixing was made, using 23% nitroglycerin, to which.had been added 0.5% of a substituted amide of an alkyl phosphate (12carbon atoms). The gelatinized composition extruded very satisfactorily.

Example 9 A gelatin mixing was made of the following compositions:

Per cent Nitroglycerin 21.0 Nitrocotton 0.5 Ammonium nitrate 12.9 Sodiumnitrate 49.8 Carbonaceous combustible material 9.0 sulfur 6.5 Chalk 0.3

Laurylamine in an amount of 0 .5% of the entire composition wasintroduced into the nitroglycerin prior to mixing. The gelatinizedcomposition nossessed satisfactory extrusion properties, whereas asimilar composition without the added plasticity promoter could not beextruded.

Example 10 A similar composition was made except that, instead of thelaurylamine, triethanolamine and sodium stearate. in amounts of 0.25%each were added to the nitroglycerin. The finished composition possessedexcellent extrusion properties.

Example 11 A seinigelatin type of composition was prepared, i. e., onecontaining a reduced amount of liquid explosive and gelatinlzing agent,sufficient to have a binding effect and to promote water resistance butinsufficient to allow the extrusion of the explosive. The compositionwas as fol- Laurylamine hydrochloride in the amount of 0.5% of theentire composition was introduced into the nitroglycerin prior tomixing. The finished composition possessed superior properties withrespect to cohesiveness and plasticity.

As is brought out in the foregoing examples, the surface active agentincluded in the explosive compositions is added to the nitroglycerin andbecomes dissolved or suspended therein. Desirarbly we use the agent inan amount not greater than 0.5% of the composition and not less than0.01%. A suitable amount is between 0.05% and 0.3%. Because of the smallquantity used, little difliculty is met in the case of any of thedesired materials in obtaining solution in the liquid explosive.

The function of the added wetting and emulsifying agent is to increasethe plasticity of gelatinous explosives containing nitroglycerin orother liquid explosive nitric ester. This is particularly important inthe case of gelatin dynamites containing relatively large amounts ofsolid inorganic nitrates, i. e., sodium nitrate or ammonium nitrate, orboth. In such explosives, it is necessary to have sufficientnitroglycerin present to allow ready extrusion of the plastic mixturethrough an orifice into the paper shells to be filled, and to maintainplasticity for use in the field. This requirement places an undesirablyhigh limit on the minimum content of liquid explosive that must be used.The presence of the surface active agents, added in accordance with thepresent invention, imparts a wetting effect to the liquid explosive sothat equivalent ease of extrusion results with markedly lower liquidcontent. For example, with a gelatinous explosive normally containing29% nitroglycerin, this content was reduced to as low as 19% by additionof a suitable plasticity promoting agent, without undesirable effect onthe extrudability, or on the explosive properties.

A considerable number of agents are adapted for effective use inaccordance with the present invention. The materials proposed willinclude, for example, esters and amides of aliphatic corboxylic acidssuch as the coconut oil acids, the esters being represented by materialssuch as long chain fatty acid esters of hexitol anhydrides, i. e. ofsorbitans, mannitant, etc., while the amides may comprise salts of fattyacid amides such as trimethyl-aminoethyloleylamide sulfate ordiethylaminoethyloleylamide acetate. A particularly preferred class ofcompounds comprises the organic soaps, for example triethanolamineoleate, the laurate and stearate of triethanolamine, etc. The solublesoaps of the alkali metals may likewise be used, as sodium and potassiumstearates. An additional desirable group of compounds comprises theorganic sulfonates, for example alkyl sulfonates, of which the dioctylester of sodium sulfosuccinic acid is an example; aryl sulfonates, e. g.the sodium salt of an aryl alkyl polyether sulfonate; and a sodiumpetroleum sulfonate. A further important class comprises the organicsulfate esters, such as the sodium salts of sulfates of the coconut oilacids, for example sodium glyceryl monolaurate sulfate. Long chainaliphatic amines and their salts have proved eifective, for examplelaurylamine and laurylamine hydrochloride. Quaternary ammonium compoundsare likewise effective, for example lauryl pyridinium chloride. Afurther group of satisfactory compounds comprises amides and esters oflong chain alkyl phosphates, the amides being represented by substitutedamides of alkyl phosphates, the alkyl group having between 12 and 18carbon atoms. As an example of suitable esters of this group, I may citethe mixed monoand dilauryl acid phosphates, or mixture of such acidphosphates of the various coconut oil acids.

As has been stated, the invention will find its principal application ingelatinized explosives containing liquid explosive nitric esters in thepresence of a considerable amount of solid ingredients, particularlyinorganic oxidizing agents. While nitroglycerin is the outstandingliquid nitric ester underlying dynamite compositions, the invention isapplicable where nitroglycols or other liquid ester equivalents havereplaced nitroglycerin, including solutions of various freezing pointdepressants in nitroglycerin. carbonaceous combustible absorbentmaterials will almost invariably be present for absorption of the liquidexplosive. The inorganic oxidizing ingredients will mainly compriseammonium nitrate and sodium nitrate, but such other agents as ammoniumand potassium perchlorates, potassium nitrate, etc. may be used. It willbe effective also with the so-called semigelatins where a considerablyreduced amount of liquid explosive is present, Where extrusion is notinvolved but better plasticity of the compositions is desired.

The invention has been described at length in the foregoing. It will beunderstood, however, that many variations may be introduced with respectto details of compositions, compositions of the surface active agents,and methods of application, without departure from the spirit of theinvention. I intend to be limited only by the following claims:

I claim:

1. A gelatinous explosive dynamite composition comprising an inorganicoxidizing agent, from 19 to 29% of a liquid explosive nitric ester, agelatinizing agent therefor, and from 0.01 to 0.5% of a surface activeagent having a non-polar group of more than eight carbon atoms, and atleast one polar group from the class consisting of hydroxy, alkylcarboxylate, amino carboxylate, sulfonate, sulfate, acid phosphateester, amino, and quaternary ammonium radicals, said compound beingtaken from the group consisting of esters and amides of long chainaliphatic carboxylic acids, soaps of organic bases and of the alkalimetals, unsubstituted aliphatic monohydric alcohols, organic sulfonates,organic sulfate esters, long chain aliphatic amines and their salts,quaternary ammonium compounds, and esters of long chain alkylphosphates.

2. The explosive composition of claim 1, in which the surface activeorganic compound is a soap of an ethanolamine.

3. The explosive composition of claim 1 in which the surface activeorganic compound is triethanolamine oleate.

4. The explosive composition of claim 1, in which the surface activeorganic compound is a laurylamine salt.

5. The explosive composition of claim 1, in which the surface activeorganic compound is an alkyl sulfonate.

6. An explosive composition as claimed in claim 1, wherein the inorganicoxidizing agent is ammonium nitrate.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,845,156 Kramer Feb. 16, 1932 2,009,028 Sibley July 23, 19352,048,050 Baker July 21, 1936 2,106,188 Power et a1 Jan. 25, 19382,159,973 Lawson May 30, 1939 2,194,544 Fassnacht Mar. 26, 19402,211,738 Cairns Aug. 13, 1940 2,235,298 Olsen Mar. 18, 1941 2,272,847Macht Feb. 10, 1942 2,385,135 Holmes Sept. 18, 1945 2,545,270 Fordham eta1 Mar. 13, 1951 2,554,180 Fordham May 22, 1951 OTHER REFERENCES TheChemistry of Powder and Explosives by T. D. Davis, vol. 11, John Wileyand Sons, N. Y., 1943, pages 288 and 289. (Copy in Scientific Library.)

1. A GELATINOUS EXPLOSIVE DYNAMITE COMPOSITION COMPRISING AN INORGANICOXIDIZING AGENT, FROM 19 TO 29% OF A LIQUID EXPLOSIVE NITRIC ESTER, AGELATINIZING AGENT THEREFOR, AND FROM 0.01 TO 0.5% OF A SURFACE ACTIVEAGENT HAVING A NON-POLAR GROUP OF MORE THAN EIGHT CARBON ATOMS, AND ATLEAST ONE POLAR GROUP FROM THE CLASS CONSISTING OF HYDROXY, ALKYLCARBOXYLATE, AMINO CARBOXYLATE, SULFONATE, SULFATE, ACID PHOSPHATEESTER, AMINO, AND QUATERNARY AMMONIUM RADICALS, SAID COMPOUND BEINGTAKEN FROM THE GROUP CONSISTING OF ESTERS AND AMIDES OF LONG CHAINALIPHATIC CARBOXYLIC ACID, SOAPS OF ORGANIC BASES AND OF THE ALKALIMETALS, UNSUBSTITUTED ALIPHATIC MONOHYDRIC ALCOHOLS, ORGANIC SULFONATES,ORGANIC SULFATE ESTERS, LONG CHAIN ALIPHATIC AMINES AND THEIR SALTS,QUATERNARY AMMONIUM COMPOUNDS, AND ESTERS OF LONG CHAIN ALKYLPHOSPHATES.